An important facet of stimulant drug use is that the drug effects can become conditioned to drug taking situations so that even during periods of abstinence exposure to such situations can trigger drug like reactions and provoked craving. In an effort to develop a more fundamental understanding of the drug conditioning process an animal model will be used which will permit a detailed characterization of the behavioral and neurochemical mechanisms which mediate drug conditioning. The animal preparation utilizes a lesion induced hemispheric dopamine asymmetry. When rodents with this asymmetry are given dopamine agonist stimulant drugs they uniformly exhibit rotational behavior. In conventional animal behavior models the specific drug induced response is frequently idiosyncratic. The consistency of the drug induced behavioral responses in the model used in this proposal permits a critical element in the conditioning process to be specified across treatment groups, namely, the unconditioned response. With this enhanced control over conditioning variables, this proposal will (a) determine the relationship of drug history to the intensity of the conditioned drug response, (b) explore methodologies which may attenuate the conditioned response, (c) examine conditioning interactions between drugs and (d) specify neurochemical correlates of the unconditioned and conditioned drug response.